Anti-roll stabilizing installation for ships

ABSTRACT

The installation is particularly useful for stabilizing ships. It comprises at least one group of two submerged tanks open to the sea, one of these tanks being provided on one side of the ship and the other on the opposite side thereof. An air compressor and a distributor ensure the distribution of compressed air in one of the tanks, resulting in the emptying of this tank, and the escape of air from the other tank, resulting in the filling of this other tank through the combined action of this escaping air. This installation additionally includes a device sensitive to the transverse inclination of the ship, and means for controlling the distributor actuated by the aforementioned device sensitive to the inclination of the ship.

United States Patent Polouektoff et al.

[ ANTI-ROLL STABILIZING INSTALLATION FOR SHIPS [72] Inventors: Jean Paul Polouektofi; Jacques de Font-Reaulx, both of Paris, France [73] Assignee: Snowball Trading Agencies S.A.,

Panama City (R. de P.), Panama 22 Filed: July 2,1970

21 Appl.No.: 51,857

[30] Foreign Application Priority Data July 15, 1969 France .....6924068 52 us. 01 ..114/12s 51 Int. Cl. ..B63b 43/06 [58] FieldofSearch ..ll4/l2l, 122, 125

[56] References Cited UNlTED STATES PATENTS 2,066,150 12/1936 Hort .Q. ..1 14/125 FOREIGN PATENTS OR APPLlCATlONS 697,545 11/1940 Germany ..1 14/125 1151 3,683,837 1451 Aug. 15, 1972 OTHER PUBLICATIONS A.P.C., U.S. Printed Application Serial No. 132,695, Published May ll, 1943 Primary Examiner-Trygve M. Blix At!0rney-Emory L. Groff and Emory L. Groff, Jr.

[ 5 7 ABSTRACT The installation is particularly useful for stabilizing ships. It comprises at least one group of two submerged tanks open to the sea, one of these tanks being provided on one side of the ship' and the other on the opposite side thereof. An air compressor and a dis tributor ensure the distribution of compressed air in.

one of the tanks, resulting in the emptying of this tank, and the escape of air from the other tank, resulting in the filling of this other tank through the combined action of this escaping air. This installation additionally includes a device sensitive to the transverse inclination of the ship, and means for controlling the distributor actuated by the aforementioned device sensitive to the inclination of the ship.

11 Claims, 12 Drawing Figures PATENTEDAUB 15 1972 SHEET 3 [If 5 fror PATENTEDMI 1972 saw u or 6 3,5 3, 37

ANTI-ROLL STABILIZING INSTALLATION FOR SHIPS This invention relates to an antiroll stabilizing installation working on compressed air intended to damp the rolling movements of a ship both during voyage and during anchorage.

The anti-roll stabilizing installation for ships according to the invention is distinguished by the fact that it comprises two submerged tanks open to the sea on either side of the ship which are filled by the hydrostatic submersion pressure, by the kinetic energy of motion and by the intake of air by a compressor, and emptied by the compressed-air pressure.

The filling and emptying of a given volume of water from the alternately functioning tanks capable of generating a correcting torque equal and opposite to the roll-producing torque with a lever arm approximately equal to the width of the ship determines the correcting movement.

A rotary air distributor consisting of four balanced valves actuated by a cam plate turning through approximately 80 and controlled hydraulically or pneumatically by piston rods, enables air to be distributed and to escape simultaneously by moving from a neutral position which eliminates water hammers and enables the two tanks to be simultaneously emptied as required.

A device sensitive to the transverse inclination of the ship comprises a float fixed to a spindle and inside a chamber filled with liquid which in turn is fixed to the ship along its transverse axis. Further means for controlling the distributor are actuated (according to the shape, inertia and velocity of the waves) by electrical signals generated by the aforementioned device sensitive to the inclination of the vessel at precise moments for changing the pumping phases.

A water jet reaction on the admission and discharge of water accumulate with the stabilizing moment.

In the accompanying drawings:

FIG. 1 is a diagrammatic view of a complete anti-roll installation according to the invention; I

FIG. 2 is a horizontal section through a submerged tank of the installation;

FIGS. 3 and 4 are vertical sections at 90 from one v another through an air distributor;

FIG. 5 is a section on the line A-B or the line A-B of FIGS. 3 and 4; 1

FIG. 6 is a section on the line CD of FIGS. 3 and 4;

FIG. 7 is an air-distribution diagram;

FIGS. 8 and 9 are stabilization diagrams;

FIG. 10 is a diagrammatic view of an anti-roll installation comprising a hydraulic roll detector according to the invention;

FIGS. 11 and 12 are partial sections through this detector on a larger scale and at 90 from one another.

The anti-roll installation according to the invention works on the principle of alternately filling and emptying two tanks C and C with a volume of water capable of generating a correcting torque equal and opposite to the roll-generating torque.

Since the two tanks are submerged below the water in voyage: a. by the hydrostatic pressure,

b. by the kinetic energy of motion of the ship, c. by the suction of the compressor. The kinetic energy of motion and the vacuum created by the compressor activate suction and ensure complete filling of the tank even if it is not completely.

submerged in the water as a result of roll.

Water is emptied from the tanks through the compressed-air pressure.

The filling time (ta may well be shorter than the delivery time (tr or vice versa, although this does not in any way prevent the installation from functioning properly.

If the installation is to operate efficiently, it must be possible for a considerable WATER-AIR volume (m /sec) to be displaced and for the filling and emptying phases to bereversed in the shortest possible time.

The present invention solves the problem as follows:

The two tanks communicate directly with the sea and the filling and emptying water flows through one or more common pipes l which, or each which, may have a non-retum valve. However, a valve or gate 2 is provided for closure after use.

There is also providedin each. tank a float valve 3 which rises when the tank is full, closes the air opening and prevents the water from entering the compressor. By virtue of this arrangement, the installation is able to function without interruption of stoppage of the compressor. In cases where the ship maintains an inclined position after one of the tanks has been filledand the other emptied, the air supplied by the compressor flows freely into the sea.

This method offers several advantages: a. it saves energy during the filling and transfer of a volume of water across the ship;

I b. there is.no need for water to be piped from one side to the other;

c. it reduces the'power required to the sole amount needed to empty the tanks;

d. no water is carried in the tanks which are emptied by compressed air after use;

e. the installation is automatically cleaned by the compressed air; v

f. for safety reasons, communication with the sea is limited by the passage of water in the water-tight tank through the pipe(s) l, with or without valves 2 The low-pressure compressed air (less than 1.5 k'g/cm") supplied by the compressor 4 travels across the ship through a flexible or rigid hose and does the mechanical work required to empty the tanks.

The air distributor 5 consists of four balanced valves 5,, S for the admission of air and E and E for the escape of air (FIGS. 3 to 6).

The compressed air arrives through an inlet 6, fills a chamber 7 containing the valves 8, and S and flows into the chambers 8 and 9 or 10 and 11, depending upon the opening of the valves. The chambers 8 and 9 are separated by a wall p and the chambers 10 and 11 by a wall p The chambers 8 and 9, and the chambers 10 and 11 are arranged on either side of the chamber 7 and another chamber 12.

The walls p and p are in a common plane while another wall 12 separating the chambers 7 and 12 is situated in a secant plane perpendicular to the plane of the walls p and p The chambers 8 and 9 communicate with one another, terminating in an opening leading to the tank C while the chambers 10 and 11 communicate with one another and terminate in an opening 0 leading to the tank C The air escaping from the tanks flows into the same chambers 8 and 9 or 10 and 11 and, after the escape valves E or E present in the chamber 12 have opened, rejoin the suction pipe 14 of the compressor which opens into this chamber 12.

The air pressure prevails between the two valves S and S and when each valves opens there is no counter pressure from the opposite side. The valve are held in position by springs 15 adjustable by a mechanism 16.

The valves are displaced by tappets l7 and rollers 18 which roll on a plate 19 carrying earns 20.

The cam plate is controlled by rods 21 of cylinder assemblies 22 and by a roller lever 23 and makes a reciprocating movement through approximately 80.

The piston rod assemblies are controlled by compressed air or hydraulically (oil) by a reversing mechanism 25 which steers the movement.

The AIR valve only opens after the escape valve has completely closed, which affords the following advantages:

1. the passage of large volumes of air with a minimum duct loss;

2. the progressive and immediate reversal of the phases in the absence of shocks and water hammers;

3. it allows the passage of impure oily air mixed with liquid, seawater in particular;

4. it does not require any special cooling to 5060.

To avoid water hammers, the two AIR valves open progressively passing through a fneutral position 24 as they do so (FIG. 7). The neutral position of the plate can be maintained pneumatically as required by progressively closing the valve 25 until the air pressures in the two piston-and-cylinder assemblies have been balanced.

The neutral position enables the two tanks to be simultaneously emptied either to balance the position of the ship or to drain the two tanks on completion of pumping. The changing of the pumping phases is controlled by a hydraulic detector 26 which records the deviation of rolls from the vertical.

This detector'detects the vertical around the roll axes, controls the heel angle, the inertia and the velocity of rolls. The sum total of the signals detected acts through an electromagnetic relay 28 on an inverter or on a two-way valve 28a which delivers air or oil under pressure supplied by a pump 29 into the pistonand-cylinder assemblies 22 controlling the distributor.

Several repeating signals reverse the phases at the required moment independently of the shape of the waves with an advance of i before the zero line of the roll which causes inertia breaking both during the descent and during the ascent of the ship.

To prevent synchronization of the rolling and stabilizing forces, the present invention provides for the generation of a zone of repeating electrical signals between more or less 42 of roll: A,, A A B B B etc. (FIGS. 8 and 9).

The effect of these contacts is to control the change in the stabilization (pumping) phases at the required time which will vary according to shape. velocity and inertia ofthe waves.

The hydraulic roll detector (or vertical deviation indicator), FIGS. 11 and 12, consists ofa horizontal float cylinder 30 fixed to a spindle 31 inside 'a chamber 32 containing a liquid (preferably oil) up to a level 33.

The chamber 32 is fixed to the deck in the transverse axis of the ship by means of two supports 35 adjustable by mechanism 36 so as to give a horizontal position to the chamber 32 when the ship has a zero list.

Bearings 34 keep the assembly in a horizontal position in the event of pitching.

In the event of rolling, the chamber 32 follows the movements of the ship, the liquid present in it and the float 30 remaining horizontal while an arm carrying an indicator 37, integral with the float, remains vertical.

The maximum deflections of the list indicator are limited to more or less 5 because the stabilizing action should begin during the first excursions from zero and should stop the roll beyond these values.

The float is balanced to a volume of approximately 30 liters and weighs about 15 kg. Hence its pressure is about 15 kg and its correcting moment ql is positive.

To ensure that the movements of the float remain regular and to ensure that the float follows the liquid level, it is provided with fins 38 level with its water line. These fins are arranged parallel to the level of the liquid.

The arm 37 is fixed to the float 30 above its center of gravity. This arm terminates in a toothed sector 39.

Two vertical arms 40'and 41 fixed to the chamber 32 above the arm 37 carry freely on a spindle 42 a shift pinion 43 which together with the chamber 32 follows the movement of the ship.

This toothed pinion 43 moves to the left and right on the toothed sector 39 which remains substantially fixed. This movement which is proportional to the port and starboard list of the ship causes the pinion to oscillate about its axis and makes a pilot spindle 44 thereof follow the curve of a dial, causing the degree of list to be recorded and at the same time electrical contacts A A A B B B etc. to be established so as to deliver a signal through a circuit 45 towards the relay 28 which acts through the inverter 28a on the air distributor S and causes the phases to be reversed.

The effect of these electrical repeating contacts is to control the change in the phases of the stabilizer at the required time which will vary between i4 according to the shape and velocityof roll.

This change in the phases preferably takes place with an advance of a" or [3 relative to the vertical, the object of which is to make it easier for the tanks to be filled and emptied.

The contacts are fixed to removable plates 46 adjustable by screws 47.

Since the dial is calibrated for a minimum roll time, the calibration is valid for all roll velocities.

A servo-pilot formed by the toothed pinion 43 is movable from left to right to actuate the contacts A A A which direct the current in the circuit 45 towards the relay 28.

By moving from right to left, the servo-pilot passes freely across the contacts A A and A and in the positions B,, E and B similarly actuated by the contactors delivers current through the circuit 48 towards the opposite side of the relay 28 which reverses the phases and determines the duration and rate of flow of the pumped water.

Several stabilizing tanks may be provided along the ship and can be brought into operation either together or separately according to the state of the sea.

In another embodiment, a gyroscope is provided to control the change in the pumping phases.

The admission and discharge of a volume of water measuring /sec at a rate of W'"/sec creates a water jet" reaction:

AR Q w sin (FIG. 1), 50, which accumulates with the stabilizing R C C /2 and the width of the ship B, the stabilizing moment is M stab R. B. "'x/,,,

By contrast, the correct torque of the ship (hull) M hull= P (-a) sin 9 Stabilization can be regarded as effective if R-B =P (6- a) sin where 6= 6 to 8 The stabilizing installation should be. calculated in such a way that it is able to develop around 80 percent of its total power seconds after the phases have been reversed.

The installation according to the invention occupies minimum space, is light and distinguished above all by its robustness, its simplicity and its ease of operation.

The principle of which it works is such that it can be included in the actual building of the ship.

Compressed air and water, even seawater, do not contain any counter-indication, which feature enables the assembly to remain in water for prolonged periods without any need for maintenance or cleaning. As it comes and goes, the compressed air automatically cleans the assembly.

The piston-and-cylinder assemblies are each equipped with a pneumatic shock damper comprising two air ducts 49 and 50.

On escaping, the air flows freely through the two orifices. At a given moment, the piston of the piston-andcylinder assembly closes the opening 49 so that the escaping air only flows through the opening 50 partially obstructed by a ball 51 which reduces shock by 90 percent in the rubber damper.

On the arrival of air, the ball 51 is lifted and enables the air to pass freely into the cylinder first through the opening 50 and then through the two openings 50 and 49.

Naturally, the invention has only been described and side of the ship and the other on the opposite side thereof, an air compressor having connected air exhaust'and air intake lines, a distributor having means communicating air escape and air intake to said tanks whereby said distributor simultaneously ensures the distribution of compressed air intake to one of said tanks, resulting in the emptying of this tank, and the escape of air from the other said tank, resulting in the filling of this other tank through the combined action of this escaping air, the hydrostatic pressure and the kinetic energy of motion when the ship moves, said dis tributor including for each tank a separate double valve through which compressed air is delivered and another separate double-acting valve through which the air escapes, detector means sensitive to the transverse inclination of the ship, and means for controlling said distributor actuated by said detector means sensitive to the inclination of the ship.

2. A stabilizing installation as .claimed in claim 1, including, a cam plate controlling said two pairs of valves .whereby, said valves of each pair through which compressed air passes only opens after said valve of each pair through which air escapes has closed completely, those valves through which compressed air passes being progressively opened and passing through a neutral position.

3. A stabilizing installation as claimed in claim 2, including push rods acting on said cam plate so that it rotates about itself in one direction or in the opposite direction through an angle of approximately 4. A stabilizing installation as claimed in claim 3, including an inverter operable to actuate said push rods.

5. A stabilizing installation as claimed in claim 4, wherein said inverter is controlled electrically by said detector means sensitive to the transverse inclination of the ship.

6. An anti-roll stabilizing installation for ships, comprising at least one group of two submerged tanks open to the sea, one of these tanks being provided on one side of the ship and the other on the opposite side thereof, an air compressor, a distributor simultaneously ensuring the distribution of compressed air in one of said tanks, resulting in the emptying of this tank, and the escape of air from the other said tank, resulting in the filling of this other tank through the combined action of this escaping air, the hydrostatic pressure and the kinetic energy of motion when the ship moves, a device sensitive to the transverse inclination of the ship, said device sensitive to the transverse inclination of the ship including a float fixed to a spindle inside a liquid-filled chamber itself fixed to the ship along its transverse axis, and means for controlling said distributor actuated by said aforementioned device sensitive to the inclination of the ship.

wherein said servo-pilot establishes electrical contacts during its .displacement so as to produce control signals.

- 10. A stabilizing installation as claimed in claim 8, wherein said servo-pilot comprises an electrical signal zone between more or less 4 of roll.

11. A stabilizing installation as claimed in claim 8, wherein said servo-pilot also forms a list indicator. 

1. An anti-roll stabilizing installation for ships, comprising at least one group of two submerged tanks open to the sea, one of these tanks being provided on one side of the ship and the other on the opposite side thereof, an air compressor having connected air exhaust and air intake lines, a distributor having means communicating air escape and air intake to said tanks whereby said distributor simultaneously ensures the distribution of compressed air intake to one of said tanks, resulting in the emptying of this tank, and the escape of air from the other said tank, resulting in the filling of this other tank through the combined action of this escaping air, the hydrostatic pressure and the kinetic energy of motion when the ship moves, said distributor including for each tank a separate double valve through which compressed air is delivered and another separate double-acting valve through which the air escapes, detector means sensitive to the transverse inclination of the ship, and means for controlling said distributor actuated by said detector means sensitive to the inclination of the ship.
 2. A stabilizing installation as claimed in claim 1, including, a cam plate controlling said two pairs of valves whereby, said valves of each pair through which compressed air passes only opens after said valve of each pair through which air escapes has closed completely, those valves through which compressed air passes being progressively opened and passing through a neutral position.
 3. A stabilizing installation as claimed in claim 2, including push rods acting on said cam plate so that it rotates about itself in one direction or in the opposite direction through an angle of approximately 80*.
 4. A stabilizing installation as claimed in claim 3, including an inverter operable to actuate said push rods.
 5. A stabilizing installation as claimed in claim 4, wherein said inverter is controlled electrically by said detector means sensitive to the transverse inclination of the ship.
 6. An anti-roll stabilizing installation for ships, comprising at least one group of two submerged tanks open to the sea, one of these tanks being provided on one side of the ship and the other on the opposite side thereof, an air compressor, a distributor simultaneously ensuring the distribution of compressed air in one of said tanks, resulting in the emptying of this tank, and the escape of air from the other said tank, resulting in the filling of this other tank through the combined action of this escaping air, the hydrostatic pressure and the kinetic energy of motion when the ship moves, a device sensitive to the transverse inclination of the ship, said device sensitive to the transverse inclination of the ship including a float fixed to a spindle inside a liquid-filled chamber itself fixed to the ship along its transverse axis, and means for controlling said distributor actuated by said aforementioned device sensitive to the inclination of the ship.
 7. A stabilizing installation as claimed in claim 6, wherein said float is provided with fins along its float line.
 8. A stabilizing installation as claimed in claim 6, wherein a servo-pilot is displaced from left to right or from right to left proportionally to the list of the ship on a sector carried by said float and remaining substantially fixed.
 9. A stabilizing installation as claimed in claim 8, wherein said servo-pilot establishes electrical contacts during its displacement so as to produce control signals.
 10. A stabilizing installation as claimed in claim 8, wherein said servo-pilot comprises an electrical signal zone between more or less 4* of roll.
 11. A stabilizing installation as claimed in claim 8, wherein said servo-pilot also forms a list indicator. 